THIS PROBABILISTIC FLOOD OUTLOOK IS FOR MISSOURI AND JAMES RIVER
BASINS OF WESTERN AND CENTRAL NORTH DAKOTA...COVERING THE TIME
PERIOD OF EARLY MARCH THROUGH EARLY JUNE.

...FLOOD OUTLOOK OVERVIEW HIGHLIGHTS....

DESPITE RECENT STORMS...DROUGHT CONDITIONS REMAIN ACROSS MUCH OF THE
MISSOURI AND JAMES RIVER BASINS. THIS PROVIDES THE REGION WITH A WELL
BELOW TO NEAR NORMAL RISK FOR SPRING FLOODING DUE TO SNOWMELT
RUNOFF. HOWEVER...THE PAST COUPLE OF WEEKS HAVE BEEN NOTABLE BY TWO
SIGNIFICANT MOISTURE PRODUCING STORMS ACROSS THE REGION. IF THIS
PATTERN WERE TO CONTINUE...THE RISK OF SPRING FLOODING DUE TO THE
INEVITABLE MELT SEASON CAN ONLY INCREASE...ESPECIALLY IF IT
COINCIDES WITH HEAVY SPRING RAINS.

WHAT IS NOT INCLUDED IN THE PROBABILITY TABLES IS THE RISK OF ICE
AFFECTED...OR ICE JAM...RELATED PROBLEMS THAT MAY ALSO CAUSE FLOODING
DURING THE NEXT FEW MONTHS.

...CURRENT CONDITIONS...

THERE ARE NO RIVER LOCATIONS IN THE MISSOURI OR JAMES RIVER BASINS
ABOVE FLOOD STAGE. RESERVOIR LEVELS ARE NORMAL FOR THIS TIME OF YEAR
AND WITHIN THE NORMAL RANGE FOR DRAWDOWN LEVELS BEFORE SPRING.

...WEATHER OUTLOOK...

A RELATIVELY WEAKER LA NINA COMBINED WITH THE POSITIVE PHASE OF THE
ARCTIC OSCILLATION HAS RESULTED IN A WARMER AND DRIER FIRST HALF OF
THE WINTER. WHILE THE REGION HAS BEEN MORE ACTIVE AS OF LATE...THE
EXTENDED FORECASTS FROM THE CLIMATE PREDICTION CENTER SUGGEST A MORE
SEASONAL EXPECTATION IN THE NEAR TERM AND A WARM MONTH OF MARCH.
HOWEVER...THE FORECASTS FOR THE MARCH...APRIL...AND MAY PERIOD
GENERALLY CALL FOR AN EQUAL CHANCE OF BELOW NORMAL...NORMAL...AND
ABOVE NORMAL PRECIPITATION AND TEMPERATURES FOR MOST OF WESTERN AND
CENTRAL NORTH DAKOTA. THIS IS LIKELY A RESULT OF CONTINUED
MODERATING LA NINA CONDITIONS THROUGH SPRING AND THE EFFECTS OF THE
POSITIVE ARCTIC OSCILLATION. IMPORTANTLY...ENOUGH OF THE WINTER
SEASON REMAINS TO PROVIDE SIGNIFICANT SNOWPACK BEFORE THE ONSET OF
THE SPRING MELT BUT THAT RISK DIMINISHES WITH EACH PASSING WEEK.

...SUMMARY OF HYDROLOGIC CONDITIONS AND SPRING EXPECTATIONS...

THE CONTINUATION OF WARM AND DRY WEATHER LEAVES THE REGION WITH BELOW
NORMAL SNOW COVER IN THE HEADWATERS OF THE SOURIS AND DES LACS
RIVERS...GENERALLY MUCH LESS THAN TWO INCHES OF WATER EQUIVALENT.
THIS LACK OF MOISTURE ACROSS THE REGION SUGGESTS THAT THE MAJORITY OF
FLOOD RISK REMAINING WOULD BE DUE TO SPRING RAINS AND UNPREDICTABLE
ICE JAMS COINCIDENT WITH THE SPRING MELT. WITH HIGHER THAN NORMAL
FLOW THROUGH THE JAMES AND OTHER SMALL RIVERS FOR THIS TIME OF
YEAR...AND A GENERALLY WARMER WINTER...IT SHOULD BE AN EARLIER THAN
NORMAL ICE FREE SEASON ACROSS THE REGION THIS YEAR. RISK OF ICE JAM
RELATED FLOODING ALONG THE MISSOURI AND SMALLER STREAMS IS GENERALLY
CONSIDERED NORMAL TO BELOW NORMAL. ONE DIFFICULT TO QUANTIFY ASPECT
OF CURRENT CONDITIONS ARE THE FULL PRAIRIE POTHOLES THAT CONTRIBUTE
TO THE JAMES RIVER BASIN...APPLE CREEK AND SOME OTHER SMALL STREAMS.
THESE WETLANDS REMAIN UNUSUALLY FULL OF WATER AND RESULT IN A LACK
OF NATURAL STORAGE WHICH COULD ENHANCE RUNOFF FROM SNOWMELT AND
SPRING RAINS.

ICE JAM RELATED FLOODING IS NOT QUANTIFIABLE...AND AS A RESULT...NOT
INCLUDED IN THE GENERATION OF THE LISTED PROBABILITIES.

...TABLE 1...PROBABILITIES FOR MINOR...MODERATE AND MAJOR
FLOODING...AND THE DEPARTURE FROM NORMAL OF REACH FLOOD STAGE...

TABLE 1. CHANCES OF EXCEEDING FLOOD STAGE AT SPECIFIC
LOCATIONS IN THE MISSOURI AND JAMES RIVER BASINS.
VALID 03 MARCH - 01 JUNE 2012

...TABLE 2...THE 90 THROUGH 10 PERCENT COLUMNS GIVEN IN TABLE 2
REPRESENT THE PROBABILITY OF THE RIVER AT A GIVEN LOCATION RISING TO
THE INDICATED STAGE LEVELS WITHIN THE NEXT THREE MONTHS.

FOR EXAMPLE...LITTLE MUDDY RIVER NEAR WILLISTON HAS A FLOOD STAGE OF 10 FEET.
IN THE NEXT THREE MONTHS THERE IS 90 PERCENT CHANCE THAT IT WILL
RISE TO AT LEAST 4.7 FEET...BUT ONLY A 10 PERCENT CHANCE THAT IT
WILL RISE TO AT LEAST 10.0 FEET.

TABLE 2. CHANCE OF EXCEEDING STAGES AT SPECIFIC LOCATIONS
ALL STAGES ARE IN FEET
VALID 03 MARCH - 01 JUNE 2012

THE NUMBERS CONTAINED IN THIS LONG-RANGE PROBABILISTIC OUTLOOK REPRESENT
NATURAL FLOWS. THAT IS...FLOW UNAFFECTED BY MAN-MADE STRUCTURES IN THE BASIN
SUCH AS DIVERSION DAMS AND RESERVOIRS.

THIS LONG-RANGE PROBABILISTIC OUTLOOK CONTAINS FORECAST VALUES THAT
ARE CALCULATED USING HISTORICAL WEATHER PATTERNS FROM 30 OR MORE
YEARS OF CLIMATOLOGICAL DATA WITH CURRENT CONDITIONS OF THE
RIVER...SNOWPACK...AND SOIL MOISTURE. BY PROVIDING THE COMPLETE
RANGE OF PROBABILITIES...THE LEVEL OF RISK ASSOCIATED WITH
LONG-RANGE PLANNING DECISIONS CAN BE DETERMINED. THESE PROBABILISTIC
FORECASTS ARE PART OF THE NATIONAL WEATHER SERVICE`S ADVANCED
HYDROLOGIC PREDICTION SERVICE (AHPS).

...ADDITIONAL HYDROLOGIC INFORMATION....

THIS OUTLOOK IN GRAPHICAL FORM ALONG WITH GRAPHS OF STAGE...FLOW...
AND VOLUME ARE AVAILABLE ON THE NATIONAL WEATHER SERVICE WEBSITE.
OTHER USEFUL LINKS INCLUDING EXPLANATIONS OF THIS PRODUCT AND
CURRENT INFORMATION FOR ALL 16 RIVER FORECAST POINTS IN THE MISSOURI
AND JAMES RIVER BASINS ARE AVAILABLE ON OUR WEB SITE. FIVE-DAY FORECASTS
ARE ALSO AVAILABLE WHEN THE RIVER AT A FORECAST POINT IS NEAR OR ABOVE
FLOOD STAGE.

VISIT OUR HOME PAGE AT: HTTP://WWW.WEATHER.GOV/BIS FOR MORE WEATHER
AND FLOOD INFORMATION.